220 OLIGOCHAETA 



with caecal diverticula. The nephridia commence in the seventh segment, but are 

 wanting in the following segments; they recommence again in the thirteenth. The 

 only two known species of the genus are European. 



(i) Claparedilla meridionalis, VEJDOVSKY. 



C. meridionalis, VEJDOVSKY, SB. Bb'hm. Ges. 1883, p. 226 (footnote). 

 Lumbriculus variegatus, CLAPAREDE, Me'm. Soc. Phys. Gen. 1862, p. 255. 

 Non-Lumbriculus variegatus, GRUBE et AuCT. 

 Pseudolumbriculus Claparedianus, DIEFFENBACH, Anat. u. Syst. Studien, p. 81. 



Definition. Prostomium as long as luccal segment; anterior perivisceral vessels in each 

 segment covered with chloragogen-cells, dilated where they join ventral vessel, and giving 

 off there four or Jive caeca ; posterior perivisceral vessels with penmate series of branches, 

 Hob. Geneva; Trieste. 



I follow VEJDOVSKY in identifying his Claparedilla with CLAPAREDE'S Lumbriculus 

 variegatus; there are, however, certain differences in the descriptions given by these 

 two writers, which are not easy to reconcile with the theory that they were 

 describing the same species. The question of the bifurcation or the non-bifurca- 

 tion of the setae has been already referred to. Of more importance, perhaps, 

 is the different account given of the vascular system ; according to CLAPAREDE 

 the two arches on either side are furnished with contractile caeca which arise only 

 on the posterior margin, in an identical position in the case of each ; on the other 

 hand, VEJDOVSKY has figured and described the posterior of the two arches alone 

 as furnished with a series (double, not single) of caeca arising along its whole 

 length ; the anterior visceral arch swells into an ampulla on the ventral side of the 

 body, just at its junction with the ventral vessel ; from this swelling are given off 

 three or four caecal appendages ; this arch alone is covered with a coating of 

 chloragogen-cells. CLAPAREDE describes the same condition as existing in this arch. 

 The dorsal vessel is covered with a coating of the same brown cells from the fourth 

 segment onwards, and the pigmented cells upon the alimentary tract commence 

 in the sixth segment at its end (CLAPAREDE). VEJDOVSKY states that the dorsal vessel 

 is covered with the pigmented cells along its entire length. DIEFFENBACH'S paper 

 dealing with the non-identity of the species termed by both CLAPAREDE and GRUBE 

 Lumbriculus variegatus, was published at about the same time as VEJDOVSKY'S 

 great work. His description of the reproductive organs of Pseudolumbriculus 

 agree with those of Claparedilla (see under Lumbriculus). 



